Unraveling Passivation Mechanism of Imidazolium-Based Ionic Liquids on Inorganic Perovskite to Achieve Near-Record-Efficiency CsPbI2Br Solar Cells

AbstractThe application of ionic liquids in perovskite has attracted wide-spread attention for its astounding performance improvement of perovskite solar cells (PSCs). However, the detailed mechanisms behind the improvement remain mysterious. Herein, a series of imidazolium-based ionic liquids (IILs) with different cations and anions is systematically investigated to elucidate the passivation mechanism of IILs on inorganic perovskites. It is found that IILs display the following advantages: (1) They form ionic bonds with Cs+ and Pb2+ cations on the surface and at the grain boundaries of perovskite films, which could effectively heal/reduce the Cs+/I− vacancies and Pb-related defects; (2) They serve as a bridge between the perovskite and the hole-transport-layer for effective charge extraction and transfer; and (3) They increase the hydrophobicity of the perovskite surface to further improve the stability of the CsPbI2Br PSCs. The combination of the above effects results in suppressed non-radiative recombination loss in CsPbI2Br PSCs and an impressive power conversion efficiency of 17.02%. Additionally, the CsPbI2Br PSCs with IILs surface modification exhibited improved ambient and light illumination stability. Our results provide guidance for an in-depth understanding of the passivation mechanism of IILs in inorganic perovskites."Image missing"

Download Full-text

Improving stability of organometallic-halide perovskite solar cells using exfoliation two-dimensional molybdenum chalcogenides

npj 2D Materials and Applications ◽

10.1038/s41699-020-00173-1 ◽

2020 ◽

Vol 4 (1) ◽

Author(s):

Meiying Liang ◽

Adnan Ali ◽

Abdelhak Belaidi ◽

Mohammad Istiaque Hossain ◽

Oskar Ronan ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Buffer Layer ◽

Perovskite Solar Cells ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer ◽

Two Dimensional ◽

Halide Perovskite ◽

The Stability

Abstract Organometallic-halide perovskite solar cells (PSCs) are emerging as the most promising next generation solar cell devices. However, the stability is still the main bottleneck of their further development. Here, we introduce two-dimensional (2D) molybdenum chalcogenides (MoS2 and MoSe2) (MCs) nanoflakes as a buffer layer between perovskite layer and hole transport layer (HTL) to improve the stability of the organometallic-halide PSCs. 2D MCs are obtained via liquid-phase exfoliated (LPE) approach, and Glass/FTO/compact-TiO2/ mesoporous-TiO2/FA85MA15PbI85Br15/2D MCs/Spiro-OMeTAD/Au structured solar cell devices are designed and fabricated. In this system, 2D MCs act both as a protective layer and an additional HTL of PSCs. This kind of PSCs achieve a relatively high-power conversion efficiency (PCE) of 14.9%, along with a much longer lifetime stability compared to the standard PSCs. After 1 h, PCE of the PSC adding a 2D MCs buffer layer could maintain 93.1% of initial value, while the PCE of the standard PSC dropped dramatically to 78.2% of initial efficiency. Our results pave the way towards the implementation of 2D MCs nanoflakes as a material able to boost the shelf life of PSCs and further provide the opportunity to fabricate large-area PSCs in view of their commercialization.

Download Full-text

Performance Improvement of All-Inorganic, Hole-Transport-Layer-Free Perovskite Solar Cells through Dipoles-Adjustion by Polyethyleneimine Incorporating

IEEE Electron Device Letters ◽

10.1109/led.2021.3058784 ◽

2021 ◽

pp. 1-1

Author(s):

Gang Lu ◽

Zeyulin Zhang ◽

Fengqin He ◽

Hailong You ◽

Dazheng Chen ◽

...

Keyword(s):

Solar Cells ◽

Performance Improvement ◽

Perovskite Solar Cells ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer

Download Full-text

Iodide-reduced graphene oxide with dopant-free spiro-OMeTAD for ambient stable and high-efficiency perovskite solar cells

Journal of Materials Chemistry A ◽

10.1039/c5ta02710a ◽

2015 ◽

Vol 3 (31) ◽

pp. 15996-16004 ◽

Cited By ~ 95

Author(s):

Qiang Luo ◽

Ye Zhang ◽

Chengyang Liu ◽

Jianbao Li ◽

Ning Wang ◽

...

Keyword(s):

Graphene Oxide ◽

Solar Cells ◽

Reduced Graphene Oxide ◽

High Efficiency ◽

Perovskite Solar Cells ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer ◽

Reduced Graphene ◽

The Stability

A p-type and highly conductive reduced graphene oxide combined with dopant-free spiro-OMeTAD as a hole transport layer improves the stability of perovskite solar cells.

Download Full-text

Performance and Life-Time Stability of Perovskite Solar Cells

International Journal of Materials ◽

10.46300/91018.2020.7.15 ◽

2020 ◽

Vol 7 ◽

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Life Time ◽

Hole Transport ◽

Absorber Layer ◽

Transport Layer ◽

Electron Transport Layer ◽

Hole Transport Layer ◽

Photovoltaic Devices ◽

The Stability

Perovskite-based solar cells have attracted a great deal of attention due to their rapid increase in power conversion, which has reached to 24.2%. The performance of perovskite solar cells depends on several parameters such as the absorber layer, the electron transport layer, the hole transport layer, and the electrodes, and the deposition technics. Moisture, oxygen, tem-perature and light intensity are environmental factors which can influence the stability of the photovoltaic devices and dete-riorate the performance. Also, the toxicity, caused by the presence of lead (Pb) content, is an obstacle for the commerciali-zation of the perovskite solar cells. The use of free-lead absorber layer is discussed, and solution to improve performances and stability of perovskite solar cells are proposed.

Download Full-text

Combination of Metal Oxide and Polytriarylamine: A Design Principle to Improve the Stability of Perovskite Solar Cells

Energies ◽

10.3390/en14165115 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5115

Author(s):

Marina M. Tepliakova ◽

Alexandra N. Mikheeva ◽

Pavel A. Somov ◽

Eugene S. Statnik ◽

Alexander M. Korsunsky ◽

...

Keyword(s):

Solar Cells ◽

Crystalline Silicon ◽

Gas Permeability ◽

Perovskite Solar Cells ◽

Hole Transport ◽

Transport Layer ◽

Hole Transport Layer ◽

Volatile Components ◽

Protective Function ◽

The Stability

In the last decade, perovskite photovoltaics gained popularity as a potential rival for crystalline silicon solar cells, which provide comparable efficiency for lower fabrication costs. However, insufficient stability is still a bottleneck for technology commercialization. One of the key aspects for improving the stability of perovskite solar cells (PSCs) is encapsulating the photoactive material with the hole-transport layer (HTL) with low gas permeability. Recently, it was shown that the double HTL comprising organic and inorganic parts can perform the protective function. Herein, a systematic investigation and comparison of four double HTLs incorporating polytriarylamine and thermally evaporated transition metal oxides in the highest oxidation state are presented. In particular, it was shown that MoOx, WOx, and VOx-based double HTLs provided stable performance of PSCs for 1250 h, while devices with NbOx lost 30% of their initial efficiency after 1000 h. Additionally, the encapsulating properties of all four double HTLs were studied in trilayer stacks with HTL covering perovskite, and insignificant changes in the absorber composition were registered after 1000 h under illumination. Finally, it was demonstrated using ToF-SIMS that the double HTL prevented the migration of perovskite volatile components within the structure. Our findings pave the way towards improved PSC design that ensures their long-term operational stability.

Download Full-text